The leading wheels having a swing bolster, and the middle pair of drivers having no flanges, the engine is guided by the truck and the front drivers, and is found to pass short curves without difficulty.
TRACTIVE POWER.
It will be seen that in engines of this pattern nearly all the weight of the machine is utilized for adhesion, only enough load being thrown on the leading wheels to steady the engine on the track. The tractive power of these engines is accordingly greater in comparison with their total weight than that of either the eight-wheeled C or the ten-wheeled D patterns, and they are, therefore, especially suited to working steep grades and hauling heavy loads at low speeds.
STRAIGHT AND WAGON-TOP BOILERS.
All the engines of this Division are built with wagon-top boilers or with straight boilers and two domes, as preferred. Where the latter form is made, the throttle-valve is placed in the forward dome. The wagon-top and straight boilers for the same class are so proportioned as to give equal steam space and the same number of flues in both forms of construction.
DIVISION IV.
FREIGHT OR PUSHING ENGINES.—"CONSOLIDATION" PATTERN.
CLASS 34 E.
ILLUSTRATED BY PRINT ON PAGE [80].
CYLINDERS.